Title :
Integrated high-T/sub c/ SQUID magnetometer
Author :
David, B. ; Grundler, D. ; Krumme, J.-P. ; Doessel, O.
Author_Institution :
Dept. of Tech. Syst., Philips Res. Lab., Hamburg, Germany
fDate :
6/1/1995 12:00:00 AM
Abstract :
We have fabricated an integrated SQUID magnetometer based on Y/sub 1/Ba/sub 2/Cu/sub 3/O/sub 7/ step-edge Josephson junctions. A tight coupling between the input coil and the SQUID washer has been achieved with a coupling coefficient K of 0.9. Noise measurements on our SQUIDs showed a nearly frequency independent flux noise of 50 /spl mu//spl Phi//sub 0///spl radic/Hz at 77 K. 1/f-noise contributions at lower temperatures were always completely suppressed by bias reversal. From our measurements of the field sensitivity and the flux noise we can estimate a field resolution of the magnetometer of 60 fT//spl radic/Hz down to 1 Hz.<>
Keywords :
1/f noise; SQUID magnetometers; barium compounds; high-temperature superconductors; superconducting device noise; yttrium compounds; 1 Hz; 1/f-noise; 77 K; Y/sub 1/Ba/sub 2/Cu/sub 3/O/sub 7/; Y/sub 1/Ba/sub 2/Cu/sub 3/O/sub 7/ step-edge Josephson junctions; bias reversal; coupling coefficient; field resolution; field sensitivity; flux noise; input coil; integrated high-T/sub c/ SQUID magnetometer; washer; Circuits; Frequency; Inductance; Josephson junctions; Magnetic field measurement; Magnetic sensors; Noise measurement; SQUID magnetometers; Superconducting coils; Yttrium barium copper oxide;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
